Synthesis of ZnO nanostructures and their medical applications

Zinc oxide nanostructures apart from being low toxic, biocompatible, and biodegradable are a diverse promising functional material that can be synthesized in different shapes, surfaces, and sizes by various methods such as green synthesis, laser ablation, sonochemical, sol-gel, and coprecipitation, etc. These nanostructures have a variety of physical and chemical properties which can be utilized in many applications including the most important biomedical applications. ZnO is a crystallite having three different phases: hexagonal wurtzite, cubic zinc blende, and rocksalt. ZnO nanoparticles are greatly reactive because of their larger surface energy and have a wide-ranging direct energy band gap (3.37eV), high excitation binding energy (60meV), and profound borderline violet and ultraviolet radiation absorption at room temperature. ZnO NPs can act against harmful bacteria, microbes, fungi, skin diseases, diabetes, and cancer, etc. These NPs alone and combined with different matrixes can also be utilized in drug delivery, bio-sensing, and bio-imaging that employs fluorescence, MRI, PET, ultrasound, and photoacoustic techniques.